Lethality : Ezreal isn't a critical character like Gangplank or Tryndamere , so that's why I don't take this mastery. He benefits more from Attack Speed , Armor pen , Magic pen or cooldown reductions.
Deadliness : For the same reasons as Lethality. 1 point is needed to acces to Tier 2 Offensive Mastery

Skill Sequence

I don't take Essence flux until I have no another choice.

Reasons : High mana cost & cooldown , low damages due to AD build. The attack speed buff it provides isn't take by ourselves. If your team is AD damages with attack speed focused ( like Yi , Ashe , Tryn etc.. ) you can put a point on it @ level 4.

Meanwhile , maximize Q skill naturally and E skill for the escape ability it provides and the damages on Trinity's or Sheen's it can proc :).

Summoner Spells

Exhaust(improved) : Place the Deadliness point into improved exhaust if you take it. The new Exhaust is better than the precedent but you mainly take it for the slow option that can be provided by the Red Buff.
Purge : Purge has been mainly nerfed , the survivability of this spell has been reduced by ~40%. It stays a good option
Teleport : Give map control , Ulti then teleport , defend a turret , shutting down a turret . But Trinity Force give good Movement Speed to travel around the map.
Clarity : If you have mana issues (like not full runes page , masteries , etc.. ) , but with my runes you don't have mana issues :).
Heal : a life saver , useful in early game. useless in late game

Bad choices :

Fortify : let a tank take it
Clairvoyance : let a support take it
Rally : You always move. Hard to profit it @ 100%
Revive : GO LAME LINE UP !

Items

Ok there is 2 build orders :

The first one ( the main page ) if you have a STRONG start ( something like more than 2 kills. )

Doran's Blade : Lifesteal , Damage , Health.
A balanced item to start. You're a Distance AD Carry. You need to don't be squishy and effective in early game.

Sword of Occult : Mass damages (8stacks and +) and M.Speed when fully stacked.
If you can't afford to stay at 8 stack or + at ~35min of the game you can sell it and take somthing that provides HP boost.

Mercury's Treads : You will be mainly focused if your job is well done. Magic res. and -40% on CC's are URGENT to take !.

League of Legends is a team based, real time strategy game set in a mythical world of swords & magic where epic battles decide the fate of mystical nations. Game players take on the role of a Summoner who conjures and controls champions to fight for them at the Institute of War. During game play champions gain experience and items to enhance their skills and abilities. How players develop and play their champions can be the difference between a crushing defeat or a glorious victory!